[untitled]

How to prompt the user to force update after the wechat applet releases a new version ！

Premise
After the applet is updated , If you do not actively delete the applet, then enter , So the small program still uses the old version code , Unable to update the latest version . In this way, if there is an urgent problem, repair it online , Users can't force updates at the first time .

terms of settlement

The official provided UpdateManager Update manager object , Used to detect whether a new version has been released .

UpdateManager Object provides the following four methods ：

UpdateManager.applyUpdate() Force the applet to restart and use the new version . After downloading the new version of the applet （ I will receive
onUpdateReady Callback ） call .

UpdateManager.onCheckForUpdate(function callback)
Listen for the event of requesting wechat background to check and update the result . Wechat automatically checks for updates when the applet is cold started , There is no need for developers to actively trigger .

UpdateManager.onUpdateReady(function callback)
The listener applet has a version update event . The client actively triggers the download （ No developer trigger required ）, Callback after successful download

UpdateManager.onUpdateFailed(function callback)
Listen for applet update failure events . There is a new version of the applet , The client actively triggers the download （ No developer trigger required ）, Download failed （ It may be due to the network, etc ） Back to

Official sample code ：

const updateManager = wx.getUpdateManager()

updateManager.onCheckForUpdate(function (res) {
    
  //  Call back after requesting new version information 
  console.log(res.hasUpdate)
})

updateManager.onUpdateReady(function () {
    
  wx.showModal({
    
    title: ' Update hints ',
    content: ' The new version is ready , Restart application or not ？',
    success: function (res) {
    
      if (res.confirm) {
    
        //  The new version has been downloaded , call  applyUpdate  Apply new version and restart 
        updateManager.applyUpdate()
      }
    }
  })
})

updateManager.onUpdateFailed(function () {
    
  //  New version download failed 
})

Official demo in , Only the most basic update tips , No exception handling . And the official also said that this function is from the basic library 1.9.90 Start supporting , Compatibility is required for the lower version .

in addition , If there are major adjustments in the current version update , Users must update , There are two situations ：

• The first method is to give a prompt in the callback when the user clicks cancel , And re enter the version prompt process .

• The second way is to remove the Cancel button , Only the OK button . Force users to upgrade , To continue to use .

The improved code is as follows ：

/** *  Detect current applet  *  Is it the latest version , Need to download 、 to update  */
function checkUpdateVersion() {
    
  // Determine whether the wechat version   Compatible with applet update mechanism API Use 
  if (wx.canIUse('getUpdateManager')) {
    
    const updateManager = wx.getUpdateManager();
    // Check for version updates 
    updateManager.onCheckForUpdate(function (res) {
    
      if (res.hasUpdate) {
    
        updateManager.onUpdateReady(function () {
    
          wx.showModal({
    
            title: ' reminder ',
            content: ' New version detected , Do you want to restart the applet ？',
            showCancel: false,
            success: function (res) {
    
              if (res.confirm) {
    
                //  The new version has been downloaded , call  applyUpdate  Apply new version and restart 
                updateManager.applyUpdate()
              }
            }
          })
        })
        updateManager.onUpdateFailed(function () {
    
          //  New version download failed 
          wx.showModal({
    
            title: ' There is a new version ',
            content: ' Please delete the applet , Re search into ',
          })
        })
      }
    })
  } else {
    
    wx.showModal({
    
      title: ' Warm tips ',
      content: ' Current wechat version is too low , This feature is not available , Please upgrade to the latest wechat version and try again .'
    })
  }
}

stay app.js Of onLaunch Add the check method to the method

//  Version automatically updates the code 
 this.checkUpdateVersion()

How to test ？
Be careful ：
Wechat developers can use 「 Compile mode 」 Under the 「 Next time you compile a simulation update 」 Switch to debug

Small program development version / The experience version doesn't have 「 edition 」 Concept , So it can't be in the development version / Test the updated version on the experience version